Interesting, I can see it fine on my end. First time I've messed with Google photos though, so maybe there's a privacy setting like Facebook uses to restrict the audience (friends vs entire world)...I'd dig into it, but I'm happy with the Smugmug.
I see the image it is a circle with a - in the center. But I am logged into google. You may need to share the image and get a different url to link it.
yeah, I kinda looked into it and saw they have shared albums and whatnot options, linking Facebook pics is a similar pita, sometimes they show, sometimes they don't...but like I said, I'm quite happy with hosting my stuff on Smugmug for $25ish bucks a year. I was mostly just curious if right clicking elsewhere brought up "copy image address" as a one click option, and it does. I can see the Adams in the vice just fine here on my end.
smugmug linked:
right click to "copy image address"
paste it into the post and highlight it.
hit the little image button up there,
click thru the prompts for location & sizing, and done.
But yeah, probably more of a hassle if you can't right click your phone or tablet...